AB0800 Ultrasonography of supraspinatus entheses in axial spondyloarthritis
Authors: C. S. Bellagha, M. Slouma, S. Ben Dhia, J. Ben Katib, L. Metoui, R. Dhahri, I. Gharsallah, B. Louzir
Journal: Annals of the Rheumatic Diseases (2022)

Background Several scoring systems have been developed to quantify ultrasound (US) abnormalities of the entheses in patients with spondyloarthritis (SpA). These scores included entheses of the lower limb, triceps tendon, and lateral epicondylar tendon [1] [2]. Studies regarding the involvement of supraspinatus enthesis in patients with SpA are scarce. Objectives This study aimed to assess the supraspinatus enthesis in patients with axial SpA using ultrasonography. Methods We performed a cross-sectional case-control study including 74 subjects (148 entheses): • G1: 37 patients with axial radiographic SpA diagnosed according to Assessment of SpondyloArthritis International Society (ASAS) criteria. • G0: 37 age and sex-matched healthy controls. All subjects underwent the US by a qualified-US rheumatologist. The long axis of the supraspinatus was assessed with the patient’s hand placed near the ipsilateral hip and the elbow directed posteriorly. Following parameters were evaluated at the bone attachment supraspinatus tendon: thickness, echogenicity, loss of normal fibrillar structure, calcifications, enthesophytes, erosions, cortical irregularities, bursitis, and vascularity at power Doppler. Statistical analysis was performed using SPSS Statistics software version 21. Results The mean age was 44.62 + 12.31 years. There were 29 men and 8 women for each group. In G1, the mean disease activity using ASDAS-CRP was 3.03 with levels ranging from 0.10 to 5.66. The mean thickness of supraspinatus tendon at its bone attachment was 4.54 ± 0.84 mm in G1 versus 4.02 ± 0.57 mm in G0 (p=0.03). Receiver Operator Curve (ROC) analysis showed the cutoff point with the best accuracy in distinguishing patients of controls to be 4.65 mm, with a sensitivity of 45.9% and specificity of 86.5% (air under the curve (AUC) value: 0.666 (p=0.014). Hypo-echogenicity and loss of normal fibrillar structure were noted in 27% (n =10 patients) and 5% (n = 2), respectively, in G1. Structural damage lesions were found in 3 % in G0 (n= 1) and 51 % in G1 (n=19), p&lt; 0.0001. In G1, structural damage lesions included: calcifications (38%, n=14), erosions (30%, n = 11), cortical irregularities (16%, n=6), and enthesophytes (8%, n=3). In G0, structural damage lesions comprised: calcifications (3%, n=1) and cortical irregularities (3%, n=1). Vascularity at power Doppler was found in 11% in G1 (n= 4) and 0 % in G0. Subacromial-subdeltoid bursitis was noted in 3% in G1 (n=1) and in 0% in G0. Conclusion Our study showed that structural damage lesions of supraspinatus enthesis were frequent in patients with SpA compared to healthy controls. A cutoff of 4.65mm supraspinatus’s thickness was able to discriminate patients with SpA from healthy controls. This finding suggests that supraspinatus enthesis evaluation can be added in entheses US scores. References [1]de Miguel E, Cobo T, Muñoz-Fernández S, Naredo E, Usón J, Acebes JC, et al. Validity of enthesis ultrasound assessment in spondyloarthropathy. Ann Rheum Dis. févr 2009;68(2):169‑74. [2]Balint PV, Terslev L, Aegerter P, Bruyn GAW, Chary-Valckenaere I, Gandjbakhch F, et al. Reliability of a consensus-based ultrasound definition and scoring for enthesitis in spondyloarthritis and psoriatic arthritis: an OMERACT US initiative. Ann Rheum Dis. déc 2018;77(12):1730‑5. Disclosure of Interests None declared